Thomas Joiner, professor of psychology at the Florida State University, led a team of researchers to examine scientific knowledge and drawing parallels between suicide in humans and the self-sacrificial behaviours of colony-like – or eusocial – species such as shrimp, mole rats and insects.

The researchers theorised that humans exhibit the characteristics of eusocial species such as relying on multi-generational and cooperative care of young and utilising division of labour for successful survival.

"Humans are a species that is eusocial, and that's an important starting point," Joiner said, adding, "that suggests a certain set of characteristics, including some really striking self-sacrifice behaviours".

Those eusocial behaviours, understood as part of what is called inclusive fitness in evolutionary biology, are adaptive.

However, when the researchers looked at human suicide in a modern context, they surmised that suicide among humans represented a derangement of the self-sacrificial aspect of eusociality.

The study findings were recently published in the journal Psychological Review.